Mounting for electrical devices



Dec. 3, 1935. E. H. JONES MOUNTING FOR ELECTRICAL DEVICES Filed Aug. 2,1933 INVENTOR E. H. JONES 8V A T TORNE Y Patented Dec. 3, 1935 UNITEDSTATES PATENT OFFICE Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation 01' New York Application August 2. 1933,Serial No. 683,245

1 Claim.

This invention relates to mountings for electrical devices and moreparticularly to sockets for electron discharge devices.

In some sockets for electron discharge devices of the type havingexternal prongs extending from the base thereof, the contact members forengaging the prongs are either exposed through a relatively largeaperture for receiving the base of the device or are disposed ad'acentan insulating member having apertures f r receiving the terminal prongs.It sometimes occurs that the contacts are connected in a circuit evenwhen no device is in the socket and there is danger, therefore, ofaccidental short-circuiting of the contact members by a tool or otherpiece of metal. There is danger also, particularly in those cases inwhich devices'utllizing relatively high potentials are employed, ofinjury to a person who accidentally comes in contact with the contactmembers.

One object of this invention is to prevent accidental short-circuitingand contact with the contact members of a socket for electron dischargedeviccs or similar apparatus.

In one embodiment of this invention, a socket comprises a base portionand a tubular portion extending therefrom and adapted to receive thebase of an electron discharge device or the like, and provided with agroove or slot for accommodating a bayonet pin projecting from the baseof the device. Contact members are mounted on the base portion of thesocket and are spaced to engage terminal prongs on the device when thelatter is inserted in the tubular portion of the socket.

In accordance with a feature of this invention, a rotatable shield ofinsulating material is mounted within the tubular portion of the socketand adjacent the contact members, and is provided with a plurality ofapertures disposed in the same geometrical relation as the contactmembers and the terminal prongs of the device. The shield member isnormally positioned so that the apertures therein are misaligned withthe contact members, thereby preventing accidental contact with thecontact members. When a device is inserted in the tubular portion of thesocket, the terminal prongs on the device enter into the apertures inthe shield member. As the device is rotated to lock the bayonet pin inthe slOt or groove therefor, the shield likewise is rotated so that theapertures therein are brought into alignment with the contact membersand the latter engage the terminal prongs. When the device is removedfrom the socket, the shield is rotated by the rotation of the device tomisalign the apertures and the contact members. Stop members may beprovided to limit the rotation of the shield to the angle of rotation ofthe device during its insertion in or withdrawal from 5 the socket. Theshield may be locked in position when the device is in the socket, by apawl or the like cooperating with a groove or notch in the shieldmember. In order to prevent accidental rotation of the shield member,friction pads, such 10 as of felt, may be provided adjacent and incontact with the peripheral portion of the shield member.

The invention will be understood more clearly and fully from thefollowing detailed description 15 with reference to the accompanyingdrawing in which:

Fig. 1 is an exploded View in perspective of a mounting constructed inaccordance with this invention, and partly broken away to show the 20insulating shield more clearly;

Fig. 2 is a side view in cross-section of the mounting shown in Fig. 1;and

Fig. 3 is a fragmentary view showing a stop arrangement for limitingrotation of the shield 25 and for preventing accidental rotationthereof.

Referring now to the drawing, the mounting comprises a hollowelbow-shaped member III, which may be of metal, having an integralflange or supporting plate portion ll provided with 30 apertures l2 forreceiving screws for securing the mounting to a. suitable support, andprovided also with an aperture l3. An insulating block it is secured tothe rear wall of the flange or plate II, as by screws l5, and hassecured thereto by 35 bolts I 6 an insulating plate I! which extendsthrough the apertures l3 into the interior of the elbow-shaped memberl0. A plurality of conductive members are mounted upon the plate l1,each of the members including an elongated strip portion l8 having aterminal portion l9 extending outwardly beyond the insulating block l4and secured to the block M as by screws 20, only one of which is shown.Each of the conducting members includes also an integral upstanding 45contact portion 2| for engaging terminal prongs 4| extending from thebase 42 of an electron discharge device or thelike, and provided with aguiding and positioning groove 22.

Another insulating block 23 is secured to the rear wall of the flange orsupporting plate H, as by screws 24, and has secured thereto by a bolt25 a conducting member including a terminal portion 26, a contactportion 21 and an inter- 55 mediate reversely bent portion 28 secured tothe insulating plate H as by a bolt 29.

The contacts 2| and 21 are disposed in the same geometrical relation asthe terminal prongs 4| of the device to be supported in the mounting. Ifthe device to be supported is an electron discharge device, the contacts2| preferably are adapted to engage the low potential terminals 01' thedevice and the contact 21 is adapted to engage the high potentialterminal. The plate l1, therefore, provides a high insulation betweenthe low and high potential contacts and prevents arcing therebetween.

The elbow-shaped member I0 is provided with an annular recess at oneend, in which the peripheral portion of a rotatable insulating disc orshield 30 is seated, the disc or shield being provided with apertures 3|disposed in the same geometrical relation as the contacts 2|I and 21. Atubular shell 32 is secured to the elbow-shaped member III as by screws33, together with a friction pad 34 of felt or similar material whichengages the disc 30 and prevents accidental rotation thereof. The shellis provided with an L-shaped groove or slot 35 for receiving a bayonetpin 43 on the device to be supported in the mounting.

The elbow-shaped member l0 may be provided with an integral inwardlyprojecting flange 36 which underlies the disc or shield 30 and hasembedded therein a pinlr31 extending into an elongated aperture or guideslot 33 in the disc or shield. The slot is so positioned that for oneextreme position thereof relative to the pin 31 the apertures 3| are inalignment with the contacts 2| and 21 and is of a length substantiallyequal to the travel of the bayonet pin 43 in the lateral arm of thegroove or slot 35.

In an alternative arrangement tor limiting the rotation of the disc orshield 30, shown in Fig. 3, the disc or shield may be provided withsuitably spaced and positioned notches 39 for receiving a spring or pawl43 mounted on the elbowshaped member I0.

Normally, that is, when the mounting is not in use, the disc or shield30 is positioned so that the apertures 3| are misaligned with thecontacts 2| and 21, and thereby prevents accidental contact from theexterior of the mounting with the contacts. When a device is placed inthe mounting, the base 42 thereof is inserted into the tubular sleeve 32with the bayonet pin 43 on the base in the vertical arm of the groove orslot 35 and the terminal prongs 4| on the base extending through theapertures 3|. As the device is rotated to lock the bayonet pin in thelateral arm of the groove or slot 35, the disc 30 is rotated until theterminal prongs 4| on the device engage the contacts 2| and 21 and areheld in the grooves 22 in the contacts. 4

When the device is to'be withdrawn from the socket, it is rotatedin-accordance with the travel of the bayonet pin in the lateral arm ofthe 5 groove or slot 35 and the disc or shield 33 is likewise rotated sothat the apertures 3| therein are misaligned with the contacts 2| and21. The rotation of the disc or shield and of the device is limited bythe pin 31 and guide slot 33 arrangement (Figs. 1 and 2) or by the pawland notch 39 arrangement (Fig. 3) and by the travel of the bayonet pinin the lateral arm or the groove or slot 35, so that at one end of thetravel the bayonet pin is in alignment with the vertical arm of thegroove or slot and the base of the device may be withdrawn from theshell 32.

It will be apparent, particularly from Fig. 2, that the disc or shield30 may be made relatively thin and that the contacts 2| and 21 may beposi- 2 tioned immediately adjacent the disc or shield. As a result, alarge portion of the terminal prongs, which are usually of a standardlength, on 1. devices such as electron discharge devices, is engageableby the contacts 2| and 21 so that a 25 large surface and low resistancecontact is established.

Although a specific embodiment of the invention has been shown anddescribed, it will be understood, of course, that modifications may bemade therein without departing from the scope and spirit of theinvention as defined in the appended claim.

What is claimed is:

A mounting for an electrical device having a base, terminal prongsextending from said base,

and a bayonet pin projecting from a wall of said base, said mountingcomprising a hollow member having a tubular portion for receiving thebase of said device and provided with a guide slot having a lateral partfor receiving said bayonet pin,

a plurality of contacts within said hollow memher and disposed in thesame geometrical relation as said prongs, an insulating shield withinsaid hollow member, having apertures for receiving said prongs andhaving also an elongated aperture adjacent its periphery, said shieldbeing rotatable in accordance with the travel of said bayonet pin insaid lateral part of said guide slot to align said apertures with saidcontacts, 50. and a pin fixed to said hollow member and extending intosaid elongated aperture, said elon gated aperture being of a lengthcommensurate with the lateral travel of said bayonet pin in said lateralpart of said guide slot. 5

EDWARD H. JONES.

